Infections caused by Ewingella americana have been rarely reported in the literature. Most of the cases that have been reported were among the immunocompromised patients. We report a case of E. The causative pathogen was identified by synovial fluid analysis and culture. Ewingella americana is a rare gram negative, lactose fermenting, oxidase negative, catalase positive, indole negative, facultative anaerobic bacillus first described from clinical specimens in by Grimont et al. It rarely causes human infections and has been identified from various clinical samples including sputum [ 2 ], conjunctiva [ 3 , 4 ], blood [ 5 — 8 ], wound [ 9 ], and peritoneal dialysate [ 10 ].
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Metrics details. Ewingella americana Ea is a Gram-negative, lactose-fermenting, oxidase-negative and catalase-positive bacterium that was first described in as a new genus and species in the family Enterobacteriaceae.
It is not known whether Ea is a true pathogen or simply an opportunistic infectious agent, as most of the cases have been described in patients at risk. Her familial and personal medical histories were negative for relevant diseases, including respiratory infections.
At admission, she was febrile axillary temperature A chest examination revealed fine crackling rales in the left upper field associated with bilateral wheezing. A chest X-ray revealed segmental consolidation of the lingula of the left lung. Laboratory tests revealed leukocytosis A nasopharyngeal swab culture did not reveal viral or bacterial respiratory pathogens, including atypical bacteria.
A blood culture revealed the presence of a Gram-negative, lactose-fermenting rod that was oxidase negative and catalase positive. The child was immediately treated orally with amoxicillin-clavulanic acid and erythromycin.
Follow-up visit 1 month later did not reveal any respiratory problems. This case shows that Ea infections in healthy subjects are mild even in pediatric age, and the need for antibiotic therapy is debated. Cases occurring in subjects with underlying chronic disease can be significantly more complicated and require appropriate antibiotic therapy. Peer Review reports.
Ewingella americana Ea is a Gram-negative, lactose-fermenting, oxidase-negative and catalase-positive bacterium that was first described by Grimont et al. Ea is very common in some vegetables and mushrooms, in which it can cause a browning disorder called internal stipe necrosis [ 2 ].
However, in humans, the detection of Ea in the tissues and bodily fluids of patients with infectious diseases is very uncommon, and the true role of this agent has not been precisely defined. Clinical infections due to Ea have been reported to cause peritonitis, conjunctivitis, bacteremia, and pneumonia [ 3 , 4 , 5 , 6 ].
Colonization in wound and sputum were also reported in patients without causing clinical infection [ 3 , 7 ]. Sepsis and even death from Waterhouse-Friderichsen syndrome due to Ea has also been reported [ 8 ]. Ea is seen in adut patients who were immunosuppressed due to diabetes mellitus, bone marrow transplantation, chemotherapy, end stage renal disease, and use of mercaptopurine [ 5 , 6 ]. However, though some cases were published in the literature, little is known about the natural habitat of Ea.
As source of infection some authors proposed the citrate solutions prepared in the hospital for coagulations study, the domestic water, the contamination of ice bath, the contamination of catheter or inadequate hand hygiene [ 9 ]. This paper reports a case of community-acquired bacteremic pneumonia due to Ea in an otherwise healthy 4-year-old girl that can be useful for increasing our knowledge regarding the clinical relevance of Ea.
The child was born at term after a normal pregnancy. At admission, her physical and neurodevelopmental growth were in the normal range. However, she was febrile axillary temperature All other systems were normal. Chest radiography and a series of laboratory tests, including a blood culture, complete blood cell count, serum C-reactive protein CRP and procalcitonin levels, liver enzymes, renal function markers, and Chlamydophila pneumoniae and Mycoplasma pneumoniae antibody concentrations were performed.
Moreover, a nasopharyngeal swab for the identification of respiratory bacteria and a Mantoux test were performed. Blood liver enzymes and renal function markers were normal. Moreover, aerosolized beclometasone in saline solution was administered two times per day. Two days after hospital admission, the resolution of her respiratory abnormalities was complete, CRP levels returned to normal values, and the aerosolized therapy was stopped.
Ea has been isolated from a variety of clinical specimens, including blood, wound swabs and sputum. Some patients have had diabetes, received immunosuppressive therapy, were HIV positive, or suffered from other chronic infections [ 14 ].
Cases in otherwise healthy subjects are very rare. This is why Ea can be considered an opportunistic bacterium. On the other hand, cases with severe clinical manifestations, including sepsis, have been almost exclusively reported in subjects who, due to their age or the presence of an underlying acute or chronic severe clinical condition, could be considered at risk of severe superimposed bacterial infections.
In healthy subjects, Ea infections are generally mild and limited to conjunctivitis and, as in the case reported here, respiratory infections with rapid favorable outcomes. Death has been described in only two cases, both in patients with conditions favoring infectious disease development, such as being at an older age and having severe traumatic injuries. The first case was that of a previously healthy old woman who suffered from Waterhouse-Friderichsen syndrome [ 8 ], while the second case occurred in a year-old man who developed nosocomial pneumonia following admission to the hospital due to a road traffic accident [ 11 ].
However, because of their underlying conditions, in this second case it was difficult to determine whether the Ea infection was indeed the cause of death [ 11 ]. Interestingly, Ea infections are even rarer in children than in adults. A case of sepsis in an infant with congenital nephropathy [ 15 ] and a case of acute conjunctivitis [ 16 ] have been described.
This is the first case of CAP due to Ea documented in an otherwise healthy child. The clinical course of this child seems to indicate that in otherwise healthy subjects Ea infections are mild and can resolve spontaneously in few days even when antibiotic treatment is not effective in vitro. At admission, blood culture results and serum Chlamydophyla pneumoniae and Mycoplasma pneumoniae antibody levels were not available.
Moreover, both the blood neutrophil count and acute phase reactant serum levels were compatible with a potential atypical bacterial etiology. As the etiology could not be determined, combined therapy with amoxicillin-clavulanic acid and erythromycin was prescribed.
However, when the results of antibiotic sensitivity tests became available, it was clear that amoxicillin-clavulanic acid could not be effective. Consequently, it seems unlikely that the very rapid favorable evolution of this case of CAP could be based exclusively on the antibiotic treatments.
However, the development of an Ea infection in patients at risk can pose difficult therapeutic problems. In these cases, antibiotics remain mandatory, but the choice is not simple. Penicillins have variable sensitivity, which explains why phenotypes with ampicillin and amoxicillin resistance seem to be inconsistent in the literature [ 18 ].
However, cases of multidrug-resistant Ea have been described in which there was a failure of the initially prescribed antibiotic therapy. Pound et al. In conclusion, this case shows that Ea infections in healthy subjects are mild even in pediatric age, and the need for antibiotic therapy is debated.
Cases occurring in subjects with underlying chronic disease can be significantly more complicated and require antibiotic therapy. The choice of the right antimicrobial can be made difficult by the emergence of resistance to first-line drugs. Ewingella americana gen. Ann Microbiol Paris. Isolation of Ewingella americana from the cultivated mushroom, Agaricus bisporus. Current Microbiol.
A case of pneumonia caused by Ewingella americana in a patient with chronic renal failure. J Korean Med Sci. A case of keratoconjunctivitis due to Ewingella americana and a review of unusual organisms causing external eye infections.
Braz J Infect Dis. Case of peritonitis caused by Ewingella americana in a patient undergoing continuous ambulatory peritoneal dialysis. J Clin Microbiol. J Antimicrob Chemother. Wound colonization by Ewingella americana. Tsokos M. Fatal Waterhouse-Friderichsen syndrome due to Ewingella americana infection. Am J Forensic Med Pathol. Ewingella americana : recurrent pseudobacteremia from a persistent environmental reservoir. Nosocomial Ewingella americana bacteremia in an intensive care unit.
Arch Intern Med. Multi-drug resistant Ewingella americana. Saudi Medical J. Google Scholar. Ewingella americana : an emerging true pathogen. Case Rep Infect Dis. Peritonitis caused by Ewingella americana in a patient with peritoneal dialysis: a case report. J Med Case Rep. Multidrug-resistant Ewingella americana : a case report and review of the literature. Ann Pharmacother. Sepsis by Ewingella americana in an infant with congenital nephropathy. An Pediatr Barc.
Maraki S. Acute conjunctivitis caused by Ewingella americana. J Pediatr Ophthalmol Strabismus. Antibiotic therapy for pediatric community-acquired pneumonia: do we know when, what and for how long to treat?
Pediatr Infect Dis J. Natural antibiotic susceptibility of Ewingella americana strains. J Chemother. Download references. WAidid had no role in the management of the case and in the preparation of the manuscript. All of the authors have read and approved the final version of the manuscript.
Metrics details. Ewingella americana Ea is a Gram-negative, lactose-fermenting, oxidase-negative and catalase-positive bacterium that was first described in as a new genus and species in the family Enterobacteriaceae. It is not known whether Ea is a true pathogen or simply an opportunistic infectious agent, as most of the cases have been described in patients at risk. Her familial and personal medical histories were negative for relevant diseases, including respiratory infections.
Ewingella Americana: An Emerging True Pathogen
Juan E. The prevalence and mycopathogenic potential of Enterobacteriaceae especially Ewingella americana in cultivated mushrooms were studied. A total of 95 samples of Agaricus bisporus , Lentinula edodes and Pleurotus ostreatus were analyzed to quantify the Enterobacteriaceae and to identify the species isolated. The host pathogenicity test was used to verify their mycopathogenic potential.
Ewingella americana is a Gram-negative rod, and the only species in the genus Ewingella. It was first identified and characterized in Ewingella is in the family Yersiniaceae. The organism is rarely reported as a human pathogen, though it has been isolated from a variety of clinical specimens, including wounds, sputum, urine, stool, blood, synovial fluid ,  conjunctiva , and peritoneal dialysate. Ewing, an American biologist who contributed to modern taxonomy. Respiratory-tract infections following retainment in intensive-care units has been observed in several instances. A case of E.
Though the pathogenic significance and the reservoir of Ewingella americana have not been clarified, this organism has caused several pathogenic infections, especially in immunocompromised patients. We report a pneumonia in a patient with chronic renal failure, who had chronic rejection of transplanted kidney. As soon as he was treated with ceftriaxone and isepamicin, clinical improvement was followed with no further growth of E. This suggests to be the case of pneumonia caused by E. Ewingella americana is the only species of the genus of Ewingella in the family Enterobacteriaceae, first described from clinical specimens in 1. The pathogenic significance and niches of the reservoir have not been clarified.